With the advancement of science and technology, touch screens have been widely applied to display devices. An existing touch screen comprises touch sensors therein, and for example, FIG. 1 is a top view of one of such touch sensors.
The touch sensor comprises a horizontal metal layer 114, a vertical metal layer 115, and a metal bridge 111 for connecting horizontal metal layers 141 on two sides in the horizontal direction, which are used for transmitting signals when the touch screen is contacted by an object. In the technology for manufacturing the above touch sensor, because an insulating layer 122 is provided between the metal bridge 111 and the horizontal and vertical metal layers 114 and 115, for making the two ends of the metal bridge 111 contact with the horizontal metal layers 114, the insulating layer 122 between the both ends of the metal bridge 111 and the horizontal metal layers 114 has to be etched off to form through holes 112, through which the horizontal metal layers 114 on both sides are conducted via the metal bridge 111. The sectional structure taken along the A′A direction of FIG. 1 is shown in FIG. 2.
The process for manufacturing the above touch sensor is described as follows.
Step A, forming a layer of metal material on a substrate and then etching the same to form a metal bridge 111;
Step B, forming a layer of PVX on the metal bridge, and then etching the same to form an insulating layer with through holes 112; the positions of the through holes 112 are, as shown in FIG. 1, at the ends of the metal bridge 111 from the above;
Step C, forming a layer of indium tin oxides ITO on the insulating layer, and then etching the same to form the vertical metal layer 115 and the horizontal metal layer 114.
The sectional structure along the B′B direction of FIG. 1 is shown in FIG. 3; and since the touch sensor is obtained through forming material layers one by one in sequence from down to top and then etching the layers, slope angles 121 will be produced during these processes, and for example the slope angles 121 produced at the lateral edges of the horizontal metal layer 114 and the vertical metal layer 115. In operation, a large amount of charges can accumulate at the slope angles 121 of the horizontal metal layer 114 and the vertical metal layer 115 during signal transmitting; if static electricity occurs when an object contacts with the touch screen, the static electricity may conduct with the charges and thus undermine the vertical metal layer, thus the vertical metal layer can not transmit signals any more, and further the whole touch screen is impaired.